Avalanche Safety & Snowmobiling

By
Eric Peterson

Avalanches that involve snowmobiles do not randomly happen. In most
Avalanche incidents the victim or another party member triggers the slide. This
tells us that these unfortunate happenings are preventable. If we choose to ride
in Avalanche terrain we are taking on inherent risks whether we realize it or
not. Education is the most powerful tool that we can use to ride safely in
Avalanche terrain. Through education and training you can gain the knowledge and
skills required to evaluate the Avalanche hazard and weigh the risks. Riding in
Avalanche terrain without the proper education, training and equipment is like
playing Russian roulette! Do you feel lucky?

Most of the Avalanches that occur in our Maritime snowpack happen during
or immediately following precipitation or wind activity. Our snowpack tends to
be deeper and stronger than the Intermountain (Idaho) and Continental (Colorado)
snowpacks. The strength of our snowpack can be a double edged sword though. Our
snowpack’s strength comes from its well bonded dense snow. This cohesive dense
snow also makes for very dangerous hard slab Avalanches. Avalanches are also
known as the “Great White Dragon”. If you use this analogy, our “Dragons” tend
to sleep more but when they awake and unleash their power they can lay a path of
destruction that’s hard to comprehend.

There are four key factors that need to be considered when evaluating the
Avalanche hazard.

1 Terrain
2 Snowpack
3 Weather
4
Human

If the terrain is not steep enough for Avalanches to occur then there is
no risk to worry about. Slope angle is the most important element of Avalanche
terrain. Avalanches can occur on slopes with angles from 25 to 60 degrees but
most often happen from 35 to 45 degrees. The prime slope angle for Avalanches to
happen is 38 degrees. Another important factor to consider is the consequences
of being swept by a slide. Even a very small Avalanche can be deadly if it takes
you off a cliff or runs you into a tree.

In regards to the snowpack we need to ask ourselves the question “could
the snow slide?” This can be a very complicated question to answer even with
years of Avalanche experience. The winter snowpack is made up of layers of snow
that represent the different precipitation events, temperature changes and wind
events throughout the winter. Our goal is to test and evaluate the strength
between these layers of snow to answer the question of stability the best we
can. An obvious clue to a present instability is observing a natural Avalanche.
If you see that an Avalanche has occurred it is safe to say that a slope with a
similar aspect (north, south, etc…) and elevation will probably slide as
well.

It has been said that weather is the architect of all Avalanches. Weather
can affects the critical balance between strength and stress within the
snowpack. Avalanches can occur as a result from weather from weeks or even
months before. Often the snowpack can not adjust to the added stress of
precipitation, extreme temperature changes or wind loading. The result can be a
failure of the bonds between the layers within the snowpack causing an
Avalanche.

Without the human factor there is no Avalanche hazard, if we are not in
the way of Avalanches how can there be a risk? This is good in theory but fails
in practice because we want to and will continue to ride in Avalanche terrain.
The key to riding safely in Avalanche terrain is to know which slopes are the
safest and to be able to perform a rescue. We all make mistakes and if one is
made evaluating the stability of the snowpack we better be able to perform and
efficient rescue. One of the basic rules of traveling in Avalanche terrain is to
expose only one rider at a time. If everybody is on the slope that Avalanches
who will do the rescuing?

Riding in Avalanche terrain without a transceiver, shovel and probe is
like riding without a helmet or driving without a seat belt, it is just plain
foolish! A transceiver is a radio beacon that can transmit and receive radio
signals. In the case of an Avalanche burial they allow you to find your buddy
very quickly. That is if you practice! Just because you carry the right rescue
equipment does not mean you are being safe. If you do not practice using your
transceiver you may cost your friend his or her life.

Here are some statistics to think about.

1 - 63% of Snowmobile
Avalanche accidents occur while highmarking. (It is very common for these
Avalanches to be triggered by a partner that is attempting to help a stuck
highmarker. Remember one rider at a time. Do not go help a stuck
highmarker!!)

2 - Since 1997 69 snowmobilers have been killed in
Avalanches.

3 - Most of these fatalities happened in Montana, Alaska,
Colorado and Idaho.

4 - Oregon has not had a snowmobile Avalanche
accident that resulted in a fatality.*This means we have been lucky not
safe.

5 - 25% of Avalanche fatalities are due to traumatic
injuries.

6 - You have a 90% chance of surviving if you’re dug out within
15 minutes.

7 - At 30 minutes you only have a 40% chance of
surviving.

8 - 64% of the survivors are rescued by their partners. You
are the rescue team!

9 - If a rescue team has to be brought in you only
have a 20% chance of surviving.

10 - Rescue doesn’t work that well. From
1950 to 1999, 682 rescues have been performed and only 292 survived. That is
only a 43% survival rate, if you get caught, buried and need rescue you don’t
even have a 50/50 chance!

To sum all this up, we need to educate ourselves about Avalanches if we
are going to ride in or near Avalanche terrain. We need to carry the appropriate
rescue equipment (transceiver, shovel and probe) and know how to use them.
Having basic first aid skills can mean the difference between life and death. We
need to ride with an open mind and open eyes so that we see the clues that
nature gives us. If we choose not to do these things we are needlessly gambling
with our lives and the lives of our friends.

Eric Peterson has gained his Avalanche experience from being a ski
patroller at Mt. Ashland for 10 years and teaching Avalanche safety and rescue.
Eric is an avid rider and enjoys the backcountry on his Ski-Doo Summit 800 as
often as he can. He is currently teaching Avalanche safety through Oregon Rescue
Technologies of Medford, OR. Thank you for reading and safe riding to
you!